Warwick physicists in Deep Underground Neutrino Experiment

University of Warwick scientists are contributing to a new particle physics experiment that will study mysterious particles called neutrinos - which could reveal why we live in a matter-dominated universe.

The Deep Underground Neutrino Experiment (DUNE), an international team of 1000 scientists from 30 countries, has officially begun with a groundbreaking ceremony one mile underground at the Sanford Underground Research Facility in South Dakota, U.S.A.

After the first shovel of earth is dug at the ceremony, more than 800,000 tons of rock —approximately the weight of eight aircraft carriers—will be excavated to create huge underground caverns. In these caverns, enormous particle detectors will be constructed and filled with liquid argon cooled to -190 degrees Centigrade.

Scientists will study the interactions neutrinos make with argon atoms in a quest to learn more about these elusive particles. The DUNE detectors will also watch for neutrinos produced by supernovae, which will enable scientists to look for the formation of neutron stars or even black holes.

"Neutrinos are the most abundant matter particles in the universe, yet very little is known about their role in the way the universe evolved", says Professor Gary Barker, who is leading the Warwick group working on DUNE.

"This new experiment will look for an answer to one of the most fundamental questions in physics: why do we see only matter in the Universe when equal quantities of matter and antimatter were created in the Big Bang? It is possible that neutrinos hold the key to this mystery, and DUNE will enable us to find out."

There are three known types of neutrino: electron, muon and tau. Neutrinos have the unusual property that they change from one type to another as they travel a few hundred km.

DUNE will make a beam of muon neutrinos at the Fermilab facility near Chicago; the properties of this beam will be first measured by a detector only 500 metres from where the neutrinos are made, which is too short a distance for changes of type to occur.

The beam will then travel 1300 km through the Earth to the huge detectors in South Dakota, which will measure it again to look for changes of neutrino type. DUNE scientists will look for differences between neutrinos and anti-neutrinos in the way they change type, which could provide essential clues as to why we live in a matter-dominated universe.

Or, in other words, why we are all here, instead of the matter contents of our Universe having been annihilated just after the Big Bang.